/Engine/Source/Runtime/PakFile/Public/IPlatformFilePak.h
Helper function to join two path strings that are in the PakPath format
static [FString](API\Runtime\Core\Containers\FString) PakPathCombine ( const [FString](API\Runtime\Core\Containers\FString) & Parent, const [FString](API\Runtime\Core\Containers\FString) & Child )